Attachment of Polymers to Organic Moieties Covalently Bonded to Iron Surfaces

This paper describes two different methods, based on the electrochemical reduction of diazonium salts, for the strong binding of polymers to an iron surface. The first method involves the electrochemical reduction, on an iron electrode, of the diazonium salt of 4-aminobenzophenone. This permits the covalent attachment of 4-benzoylphenyl moieties on the surface. Polystyrene (PS) is then deposited on the modified iron surface and can be covalently bonded to the 4-benzoylphenyl groups under irradiation. Another method involves the attachment of carboxyphenyl groups to the iron surface by reduction of the diazonium salt of 4-aminobenzoic acid and the further attachment of poly(1,2-propanediyl fumarate) to the phenylcarboxylate functions through ionic bonds with Mg 2+ ions. The barrier properties of the polymeric films are characterized by electrochemistry and by the protection they provide against corrosion.